wireguard-linux/net/core/net_namespace.c, branch jd/bump-compilers

net: Initialise net.core sysctl defaults in preinit_net().

2024-08-03T21:38:45Z

Commit 7c3f1875c66f ("net: move somaxconn init from sysctl code") introduced net_defaults_ops to make sure that net.core sysctl knobs are always initialised even if CONFIG_SYSCTL is disabled. Such operations better fit preinit_net() added for a similar purpose by commit 6e77a5a4af05 ("net: initialize net->notrefcnt_tracker earlier"). Let's initialise the sysctl defaults in preinit_net(). Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

net: Slim down setup_net().

2024-08-03T21:38:45Z

Most initialisations in setup_net() do not require pernet_ops_rwsem and can be moved to preinit_net(). Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

net: Call preinit_net() without pernet_ops_rwsem.

2024-08-03T21:38:44Z

When initialising the root netns, we call preinit_net() under pernet_ops_rwsem. However, the operations in preinit_net() do not require pernet_ops_rwsem. Also, we don't hold it for preinit_net() when initialising non-root netns. To be consistent, let's call preinit_net() without pernet_ops_rwsem in net_ns_init(). Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

net: Initialise net->passive once in preinit_net().

2024-08-03T21:38:44Z

When initialising the root netns, we set net->passive in setup_net(). However, we do it twice for non-root netns in copy_net_ns() and setup_net(). This is because we could bypass setup_net() in copy_net_ns() if down_read_killable() fails. preinit_net() is a better place to put such an operation. Let's initialise net->passive in preinit_net(). Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

net: Don't register pernet_operations if only one of id or size is specified.

2024-08-03T21:38:44Z

We can allocate per-netns memory for struct pernet_operations by specifying id and size. register_pernet_operations() assigns an id to pernet_operations and later ops_init() allocates the specified size of memory as net->gen->ptr[id]. If id is missing, no memory is allocated. If size is not specified, pernet_operations just wastes an entry of net->gen->ptr[] for every netns. net_generic is available only when both id and size are specified, so let's ensure that. While we are at it, we add const to both fields. Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

netns: Make get_net_ns() handle zero refcount net

2024-06-18T08:59:52Z

Syzkaller hit a warning: refcount_t: addition on 0; use-after-free. WARNING: CPU: 3 PID: 7890 at lib/refcount.c:25 refcount_warn_saturate+0xdf/0x1d0 Modules linked in: CPU: 3 PID: 7890 Comm: tun Not tainted 6.10.0-rc3-00100-gcaa4f9578aba-dirty #310 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:refcount_warn_saturate+0xdf/0x1d0 Code: 41 49 04 31 ff 89 de e8 9f 1e cd fe 84 db 75 9c e8 76 26 cd fe c6 05 b6 41 49 04 01 90 48 c7 c7 b8 8e 25 86 e8 d2 05 b5 fe 90 <0f> 0b 90 90 e9 79 ff ff ff e8 53 26 cd fe 0f b6 1 RSP: 0018:ffff8881067b7da0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff811c72ac RDX: ffff8881026a2140 RSI: ffffffff811c72b5 RDI: 0000000000000001 RBP: ffff8881067b7db0 R08: 0000000000000000 R09: 205b5d3730353139 R10: 0000000000000000 R11: 205d303938375420 R12: ffff8881086500c4 R13: ffff8881086500c4 R14: ffff8881086500b0 R15: ffff888108650040 FS: 00007f5b2961a4c0(0000) GS:ffff88823bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d7ed36fd18 CR3: 00000001482f6000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? show_regs+0xa3/0xc0 ? __warn+0xa5/0x1c0 ? refcount_warn_saturate+0xdf/0x1d0 ? report_bug+0x1fc/0x2d0 ? refcount_warn_saturate+0xdf/0x1d0 ? handle_bug+0xa1/0x110 ? exc_invalid_op+0x3c/0xb0 ? asm_exc_invalid_op+0x1f/0x30 ? __warn_printk+0xcc/0x140 ? __warn_printk+0xd5/0x140 ? refcount_warn_saturate+0xdf/0x1d0 get_net_ns+0xa4/0xc0 ? __pfx_get_net_ns+0x10/0x10 open_related_ns+0x5a/0x130 __tun_chr_ioctl+0x1616/0x2370 ? __sanitizer_cov_trace_switch+0x58/0xa0 ? __sanitizer_cov_trace_const_cmp2+0x1c/0x30 ? __pfx_tun_chr_ioctl+0x10/0x10 tun_chr_ioctl+0x2f/0x40 __x64_sys_ioctl+0x11b/0x160 x64_sys_call+0x1211/0x20d0 do_syscall_64+0x9e/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5b28f165d7 Code: b3 66 90 48 8b 05 b1 48 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 8 RSP: 002b:00007ffc2b59c5e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5b28f165d7 RDX: 0000000000000000 RSI: 00000000000054e3 RDI: 0000000000000003 RBP: 00007ffc2b59c650 R08: 00007f5b291ed8c0 R09: 00007f5b2961a4c0 R10: 0000000029690010 R11: 0000000000000246 R12: 0000000000400730 R13: 00007ffc2b59cf40 R14: 0000000000000000 R15: 0000000000000000 Kernel panic - not syncing: kernel: panic_on_warn set ... This is trigger as below: ns0 ns1 tun_set_iff() //dev is tun0 tun->dev = dev //ip link set tun0 netns ns1 put_net() //ref is 0 __tun_chr_ioctl() //TUNGETDEVNETNS net = dev_net(tun->dev); open_related_ns(&net->ns, get_net_ns); //ns1 get_net_ns() get_net() //addition on 0 Use maybe_get_net() in get_net_ns in case net's ref is zero to fix this Fixes: 0c3e0e3bb623 ("tun: Add ioctl() TUNGETDEVNETNS cmd to allow obtaining real net ns of tun device") Signed-off-by: Yue Haibing Link: https://lore.kernel.org/r/20240614131302.2698509-1-yuehaibing@huawei.com Signed-off-by: Paolo Abeni

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2024-05-09T17:01:01Z

Cross-merge networking fixes after downstream PR. No conflicts. Adjacent changes: drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c 35d92abfbad8 ("net: hns3: fix kernel crash when devlink reload during initialization") 2a1a1a7b5fd7 ("net: hns3: add command queue trace for hns3") Signed-off-by: Jakub Kicinski

net: fix out-of-bounds access in ops_init

2024-05-06T11:38:14Z

net_alloc_generic is called by net_alloc, which is called without any locking. It reads max_gen_ptrs, which is changed under pernet_ops_rwsem. It is read twice, first to allocate an array, then to set s.len, which is later used to limit the bounds of the array access. It is possible that the array is allocated and another thread is registering a new pernet ops, increments max_gen_ptrs, which is then used to set s.len with a larger than allocated length for the variable array. Fix it by reading max_gen_ptrs only once in net_alloc_generic. If max_gen_ptrs is later incremented, it will be caught in net_assign_generic. Signed-off-by: Thadeu Lima de Souza Cascardo Fixes: 073862ba5d24 ("netns: fix net_alloc_generic()") Reviewed-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240502132006.3430840-1-cascardo@igalia.com Signed-off-by: Paolo Abeni

netns: no longer hold RTNL in rtnl_net_dumpid()

2024-04-18T01:30:28Z

- rtnl_net_dumpid() is already fully RCU protected, RTNL is not needed there. - Fix return value at the end of a dump, so that NLMSG_DONE can be appended to current skb, saving one recvmsg() system call. Signed-off-by: Eric Dumazet Reviewed-by: Guillaume Nault Link: https://lore.kernel.org/r/20240416140739.967941-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: use synchronize_rcu_expedited in cleanup_net()

2024-02-12T12:17:03Z

cleanup_net() is calling synchronize_rcu() right before acquiring RTNL. synchronize_rcu() is much slower than synchronize_rcu_expedited(), and cleanup_net() is currently single threaded. In many workloads we want cleanup_net() to be fast, in order to free memory and various sysfs and procfs entries as fast as possible. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller